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Full text of "Alaskan glacier studies of the National Geographic Society in the Yakutat Bay, Prince William Sound and lower Copper River regions"

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VALDEZ AND SHOUP GLACIERS                             239
has one south tributary. Its end is heavily covered with moraine and completely disconnected from Valdez Glacier.
Between the terminus of Valdez Glacier and Port Valdez are three and a ha,Tf miles of outwash gravel plain with many occupied and abandoned stream courses, a few knobs of dissected outwash gravels and recessional moraines, and, near Valdez, a strip of forest.
Observations Prior to 1898. Vancouver's lieutenant, "Whidbey, entered Puerto de Valdes on June 10, 1794, making the first map of it and showing its head about half Way between Valdez Narrows and the present terminus. He sailed northeast for twelve miles, or to what we now call Valdez Narrows, where he states * that a "small brook, supplied by the dissolving of the ice and snow on the mountains, flowed into the arm, which about five miles from thence terminated in an easterly direction." The latitude given and the shape of the fiord are essentially correct except that it does not extend eastward as far as now; but no glaciers are mentioned. Whidbey speaks of the region being in the same latitude as what we now call Columbia Glacier where they had observed great falls of ice, and of their surprise in Port Valdez that "in this branch no ice has been seen, notwithstanding it is terminated by shallow water at its head, and is surrounded by similar steep frozen mountains." Davidson has looked into Whidbey's description and believesa that if the shore on Whidbey's map "really was the limit of the bay, and the water was found shallow, then the whole eastern half of the Port, with its one hundred and fifty fathoms depth, was occupied by a low moraine-covered glacier that hid the ice front."
We are not convinced of the correctness of this interpretation, partly because no thundering ice falls or floating icebergs are mentioned, as would be necessary with the existing depth of the fiord, partly because the original account does not prove that Whidbey went far enough through the Narrows to see the whole length of Valdez Arm and the Shoup and Valdez Glaciers, but chiefly because eastern Prince William Sound does not seem to have had such a recent episode of ice advance as is shown in Yakutat and Glacier Bays. An eight or nine-mile retreat for Valdez Glacier between 1794 and 1898 is not impossible, but, if Davidson's interpretation is correct, the vegetation has followed the ice front much more closely here than in similar cases we have observed in Alaska, for in 1909 spruce was growing at Valdez and cottonwood and alder extended right up to the glacier. Moreover, if Valdez Glacier was so extensive in 1794, even if moraine-covered and not discharging icebergs, and not recognized as a glacier, Shoup Glacier should have been similarly expanded and must have been visible to Whidbey from the Narrows, should have discharged icebergs, and should have spread over slopes that are now too well tree-covered to have been reforested in the years between 1794 and 1898. Another objection to this theory of recent great expansion of Valdez Glacier is the presence of the very extensive outwash gravel plain which extends from the Valdez Glacier front three and a half miles to the head of the fiord. A long period of time has been required to build this gravel plain, even assuming former shallow water where it stands; and, moreover, mature cottonwood trees have had time to grow upon it since it was built above sea level.
i Vancouver, Capt. George, A Voyage of Discovery to the North Pacific Ocean and Around the World, Vol. V, London, 1801, pp. 317-8.
' Davidson, George, The Glaciers of Alaska that are Shown on Russian Charts or Mentioned in Older Narratives, Trans, and Proc. Geog. Soc., Pacific, Vol. HI, 1904, pp. 35-6.